Aircraft fuel injection system



United SW65 Pate Q C? The present inventionrelates generally to the aircraft engine art and more particularly to a novel aircraft fuel 7 injection system for piston-type aircraft.

Briefly stated, one embodiment of the present invention includes the combination of an impeller air intake section of a piston-type aircraft engine containing a rightangle passageway with arcuate turning vanes in the passageway," and a fuel injector nozzle positioned upstream of the right-angle passageway and the turning vane. The nozzle preferably extends normal to the flow of air and contains an opening at the inner endthereof for emitting fluid fuel in the form of a conical spray. a i

As is well known in the art, the use of float-type carburetors with piston aircraft engines has not been com pletely satisfactory because of icing problems and relatively low operational performance. Consequently, much time and effort has been directed toward the utilization tion having a right-angle passageway containing arcuate i turning vanes downstream of the fuel regulator, a fuel injector nozzle placed in the right-angle passageway can be adjusted to operate satisfactorily for the one engine but the same position and adjustments will not operate satisfactorily on a different engine of the same type and size because of the dilferences in the, internal dimensions of the crankcases.

It is an object of the present invention, therefore, to

provide a novel aircraft fuel injection system for certain piston-type aircraft engines which will overcome the icing problems and low operational performance present when float-type carburetors are used therewith.

Another object is to provide such a system which will operate satisfactorily with all piston-type engines of a panticular type and size. More particularly, it is an object to provide a fuel injector to impeller air intake section relationship which will provide satisfactory fuel injection operation regardless of the irregularities of the impeller air intake sections and the differences in internal dimensions thereof even when they are of the same size and design. I a 1 Yet another object is to provide a fuel injection system for piston-typeaircraftengines which provides an improved fuel-air distribution over the fuel-air distribution achievedwith a standard float-type carburetor. More particularly, it is an object to provide such an injection system in which there is as much as a fifty percent improvement in fuel distribution as compared with a conventional float-type carburetor.

Further objects and advantages of the present invention will be apparent from the following detailed description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is shown.

In the drawings:

FIG. 1 is a front elevational view of the impeller air intake section of a piston-type aircraft engine provided with a novel fuel injection system constructed in accordance with the teachings of the present invention;

3,166,059 a n d J i 1.? 1 65 FIG. 2 is a vertical sectional view taken on the line 2--2 in FIG. 1; and r FIG. 3 is an enlarged fragmentary sectional view taken on the line 33 in FIG. 1. I

As indicated hereinabove, the manufacturing tolerances on the impeller air intake sections of piston-type aircraft engines'are'relatively large and therefore there is considerable difference between the internal dimensions of the cases even though they are for the same size and type of engine. It is this difference in manufacturers tolerances on both external andintern'al dimensions which presented the greatest problem'in providing a fuel injection system of universal application. This problem was solved by the instant construction which provides uniformly consistent fuel-air distribution in each engine regardless of theidilfere nce in impeller air intake section dimensions. As will be described'more fully hereinafter, this result was achieved by placing the fuel injector upstream from the right-angle bend and the arcuate turning vanes and spraying the fuel into the air stream in the form of a conicalspray substantially normal to the flow of the air.

Referring to the drawing more particularly by reference numerals, 10 indicates a conventional impeller air intake section of a piston-type aircraft having associated therewith a fuel-injection system embodying the teachings of the present invention. The impeller air'intake section 10 contains an inlet or outer end 12 andau inner end 14. Adjacent the inner end 14 is an engine impeller 16 and upstream of the impeller is a right-angle passageway 18 containing a. plurality. of radially spaced arcuate turning vanes 20. I

Connected to the outer end of the impeller air intake section is the upper end of a tubular adapter 22 which contains a sidewall 24 with a smooth inner surface 26 and containing an outwardly extending cylindrical protuberance 28 with a hat mounting surface 30 for receiving a fuel injector nozzle assembly 32. A cylindrical passageway 34 extends through the protuberance from vthe'inner surface 26 to the mounting surface 30.

The nozzle assembly 32 includes a housing 36 which is removably mounted on the surface 30 by any suitable means such as machine screws,. and a nozzle 38 which extends through thepassageway'34 and into the interior of the adapter 22. In one embodiment of the present invention, the inside diameter of the adapter 22 at the nozzle is about three inches, and the nozzle projects inwardly about one-half inch so that the'ratio of projectionto diameter is about oneto six, 1 j Q As shown in FIG. 3, the'nozzle 38 contains a coneshaped movable head 40 which provides a conical spray of fuel into the interior of the adapter 22, the movement of the head 40 relative to the nozzle body con- .tro-lling the thickness or amount of fluid fuel in aconventional manner. The housing 36 contains a fuelsupply inlet 42 which is: in direct communication withthe nozzle previously described, and'a' T-shaped servo fitting 44 which is in communication with the back side of a contank and the other ends of the fuel supply and serve hoses are connected to a fuel regulator or metering unit 56 which is fastened to the lower end of the tubular adapter 22 and which will now be described.

The metering unit 56 functions in a known manner to control the flow of fuel to thenozzle and the pressure on the diaphragm' previously described, and includes a throttle control arm 58, a mixture control arm 60, a main 1 fuel inlet 62, a servo outlet 64 which is connected to the other. endp the servo hos nd a ue pp y outlet 66 which is-connected to the other end of the fuel supply hose'50.fr

In operation, fuel 7 the main fuel inlet 62 and passes therefrom through the servo hose outlet. and the fuel supplyhose outlet 66.

,The fuelwhich passes through the servo} hose 52 and into,

enters the metering unit 56 through v cylinders, an impeller for v manifold and an impeller air intake section containing pressurizing air flowing to if the a right angle passageway therethrough provided ,with

, arcuate turning vanes, the combination of tubular. means connected to an inlet of the impeller air intake section and having an opening therethrough for the passage of air and containing a side wall, a fuel injector nozzle mount- 7 ed on said side wall and extending into the passageway substantially normal to the "direction of air flow therethrough, a fuel conduit connected-to supply pressurized fuel to said fuel injection nozzle, and control means opviously described. In the adapter, the fuel mixes with the incoming air and directed through the passageway 18 by the arcuate turning vanes 20 and into'the eye of the impeller 16. Beyond the impeller the fuel mixture is channeled through a manifold (not shown) or directly into a Icylinder.

Because the fuel is injected in the stated manner upstream of the impeller air intake section, the dilferen ce in the dimensions between different impeller air intake sec- .tions of the same type and size does not adversely aifect the fuel-air distribution, and therefor each installation achieves consistently good results as to fuel-air distribution and as much ,asa fifty percent improvement is achievedcompared with'conventional float-type carburetor. systems; V

7 Thus, it is apparent that there has been provided a novel aircraft'fuel injection system for piston-type aircraft engines which fulfills all of thebbjects and advantages sought-therefor. -It is'to be understood that the foregoing description and the accompanying drawings have been given only by way of illustration and example and that changes and alterations in the present disclosure which'will be readily apparent to one skilled in the art e contemplated as withinthe scope of the present invention. We'claim: p

3 1. 111 fuel supply apparatus for a combustion-engine having a manifold in communication with a plurality of cylinders, an impeller for pressurizing airflowing to the manifold and an impeller air intake section containing a right angle passageway therethr'ough provided with arcuate turning vanes, the combination of tubular means connected. to an inlet of the impeller air intake section and :having a passageway ,therethrough for the passageof air and containing a sidewall, a fuel injector nozzle mounted pnsaid sidewall and projecting into said passageway for injecting fuel into 'said tubular means substantially normal to the direction of air flowvtherethrougma fuel" conduit connected, to supply pressurized fuel to said fuel injection nozzle, and control means operatively connected to said fuel conduit for controlling the flowof fuel therethrough to said nozzle. 7 D

2, In fuel supply apparatus for a combustion engine having a manifold in communication. with a plurality of eratively connected to said fuelconduit for controlling the flow of fueltherethrough to SaldI1OZZl6. a

3. In fuelsupply' apparatus'for a combustion engine having a manifoldinjcommunication with a plurality of cylinders, an impeller for pressurizing air fiowing to the manifold and an impeller air intake section containing a right anglepassageway therethrough provided with arcuate V V turning vanes, the combination of tubular means con? nected to an inlet of, the impeller'air intake section and "having an opening therethroughfor the passage of air and containing a side wall, a fuelinjector nozzle mounted on said side wall and extending into the passageway transversely' to the air flow therethrough a distance substan- 'tially less than the radius thereof, said nozzle having an opening in the end thereof from which fuel is injected in the form of a conical spray to said air flow, and control means operatively connected to said ,fuel conduit for controlling the flow of fuel therethrough to said nozzle. 4. Fuel supply apparatus for a combustion engine having a manifold in communication with a plurality of cylinders, an'air impeller for supplying'air to the manifold and an impeller air intake section having a right angle passagewaytherethrough connected to supply air tothe impeller, the combination of tubular means connected to the inlet of the'impeller air intake section and provided with a side wall, control means including a venturi and an air throttle valve for controlling the flow of air to said tubular means, a fuel injector nozzle mounted on said side wall downstream from said venturi and air throttle valve and projecting irito said tubular means normal to' the direction'of air flow 'therethrough, a fuel conduit connected to supply' pressurized fuel to said fuel injector nozzle, means operatively connected to said fuel conduit for controlling fuel flow therethrough, and arcuate turning vanes operatively connected to the right angle passageway for guiding the. flow of air-fuel mixture therethrough.

I 5. Fuel supplvapparatus as claimed in claim 4 wherein said fuel injector nozzle projects into said passageway a distance such that the ratio of the amount of projection compared with the inside diameter of said passageway is in the ratio of about one to six.

References Cited in the file of this patent UNITED STATES PATENTS -"1,s97,191' Farina Feb. 14, 1933 1,933,330 Mock et a1. Oct. 31, 1933 "2,099,785 Willgoos Nov. 23, 1937 Haltenberger lune 2, 1953 

1. IN FUEL SUPPLY APPARATUS FOR A COMBUSTION ENGINE HAVING A MANIFOLD IN COMMUNICATION WITH A PLURALITY OF CYLINDERS, AN IMPELLER FOR PRESSURIZING AIR FLOWING TO THE MANIFOLD AND AN IMPELLER AIR INTAKE SECTION CONTAINING A RIGHT ANGLE PASSGEWAY THERETHROUGH PROVIDED WITH ARCUATE TURNING VANES, THE COMBINATION OF TUBULAR MEANS CONNECTED TO AN INLET OF THE IMPELLER AIR INTAKE SECTION AND HAVING A PASSAGEWAY THERETHROUGH FOR THE PASSAGE OF AIR AND CONTAINING A SIDE WALL, A FUEL INJECTOR NOZZLE MOUNTED ON SAID SIDE WALL AND PROJECTING INTO SAID PASSAGEWAY FOR 